(WPRI/AP) — Baby gates meant to protect young children aren’t always as safe as parents think. A new study says nearly 2,000 U.S. kids get emergency room treatment each year from injuries resulting from falling through or climbing on these gates.

Most injuries weren’t serious. But the researchers say parents should know about precautions. That includes using bolted gates, not pressure-mounted ones, at the top of the stairs.

Researcher Lara McKenzie and colleagues at Nationwide Children’s Hospital in Columbus, Ohio, examined data on kids up to age 6. The number injured on gates more than tripled over 20 years. These cases climbed from about 4 per 100,000 children in 1990 to almost 13 per 100,000 in 2010.

“Parents are trying to do the right thing in terms of keeping their child protected, the bad news is that they may not always be installing the right type of gate in the right area,” said McKenzie.

According to Hasbro Children’s Hospital, four children were treated for injuries from baby gates last year, and one case this past March.

The study was published online Monday in the journal Academic Pediatrics.